Manually operated boat lifts are frequently employed to lift a boat out of the water and lock the boat in an elevated position. The typical boat lift includes a frame which is mounted on the bed of the body of water, and the frame carries a movable sub-frame that can be moved by a winch mechanism from a lower, submerged position to an elevated position to thereby lift the boat from the water.
The conventional winch mechanism includes a large diameter hand wheel and rotation of the hand wheel operates through a chain drive speed reducing mechanism to rotate the winch drum and thereby wind the cable on the drum to lift or elevate the boat. More particularly, in the conventional winch mechanism, the hand wheel is secured to an annular hub that is threaded on the end of a shaft. Rotation of the hand wheel in the elevating mode will move the hub axially on the shaft to engage a brake pad that is attached to one surface of a rachet plate. A second brake pad attached to the opposite surface of the rachet plate is engaged with a backing plate secured to a side plate of the winch. With this construction, a predetermined amount of axial movement of the hub on the shaft will engage the brake pads so that further rotation of the hand wheel will rotate the shaft. Rotation of the shaft is transmitted through one or more speed reducing mechanisms to the drum shaft to thereby rotate the drum and wind the cable on the drum and elevate the boat.
It has been found that when employing brake pads attached to opposite surfaces of the rachet plate, the hub and backing plate tend to dig into the pads so that the brake will not readily release upon opposite rotation of the hand wheel. Often, it is necessary to jerk the winch to provide a release.
As the chain drive speed reduction units in the winch constructions of the past have been located between the side plates of the winch, there has been no ability to readily vary the speed reducing ratio. Further, due to the fact that the chain drives of the prior winch constructions were located between the side plates, the winch could not be reversed from left to right with respect to the boat lift frame so that separate right and left winches have been required to accommodate the desired location of the winch.